Data classification methods and apparatus for use with data fusion

ABSTRACT

Methods and apparatus for classifying data for use in data fusion processes are disclosed. An example method of classifying data selectively groups nodes of a classification tree so that each node is assigned to only one of a plurality of groups and so that at least one of the groups includes at least two of the nodes. Data is classified based on the classification tree and the selective grouping of the nodes, and the results displayed.

RELATED APPLICATIONS

This patent is a continuation of U.S. patent application Ser. No.11/692,480 filed Mar. 28, 2007, now U.S. Pat. No. ______, which claimspriority from PCT International Application Serial No.PCT/US2004/031965, entitled “Data Classification Methods and Apparatusfor Use with Data Fusion,” filed on Sep. 28, 2004, each of which ishereby incorporated by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to processing databaseinformation and, more specifically, to data classification methods andapparatus for use in fusing multiple databases into a single database.

BACKGROUND

Successful planning, development, deployment and marketing of productsand services depend heavily on having access to relevant, high qualitymarket research data. Companies have long recognized that improving themanner in which marketing data is collected, processed, and analyzedoften results in more effective delivery of the right products andservices to consumers and increased revenues. Recently, companies havesought to more effectively target marketing efforts toward specificgroups or individuals having certain combinations of demographiccharacteristics and psychographic profiles. Such highly targetedmarketing efforts may provide a company a significant competitiveadvantage, particularly for highly competitive markets in whichincreased revenues are obtained primarily as a result of increasedmarket share.

Market researchers have long dealt with the practical tradeoff betweenthe desire to develop database information that enables companies todevelop and deploy highly targeted marketing plans and the desire todevelop database information that is more versatile in its applicationor utility. For example, a database developed from a respondent panel orsurvey that has been narrowly tailored to provide information related tothe television viewing behaviors of a particular regional populationhaving a particular demographic profile may be of little, if any, usewhen attempting to determine the fast food consumption habits of anotherpopulation having that same demographic profile.

In response to the practical difficulties (e.g., the cost) associatedwith assembling market research panels or surveys covering multipletypes of consumption activities, behaviors, preferences, etc., marketresearchers have employed database fusion techniques to efficientlymerge or fuse database information from multiple research panels orsurveys (typically two at a time) into a single database representing asingle virtual population group or respondent-level panel. It is wellknown that the fusion of two datasets or databases into one dataset ordatabase may enable the development of a database that revealscorrelations between the consumption activities, preferences, etc.associated with two datasets or databases in a manner that theindividual datasets could not. In other words, existing market researchdatabases can be combined or fused in different ways to generate newdatasets or databases that reveal respondent behaviors and/orrelationships not previously revealed by the independent databases,without having to physically develop and pay for an expensivemulti-purpose respondent panel or survey.

Typically, the fusion of databases or datasets involves a statisticalanalysis to identify a mathematical function that can be used to predictrespondent usage patterns. In general, the mathematical functionproduced as a result of the statistical analysis is used to guide orfacilitate the process of matching observations or records in thedatasets or databases to be fused. In some cases, known distancefunction techniques are used to measure the similarities betweenobservations or records. In other cases, the statistical analysis mayprocess usage data using regression modeling techniques to identifythose variables that are common to the databases or datasets to be fusedand best suited to match observations or records.

To simplify and/or enhance a data fusion process, it is often desirableto group or segment database observations or records, each of whichtypically corresponds to a particular person, respondent, or household,according to a plurality of classes, or groups representing differenttypes or levels of consumption behavior (e.g., non-consumers, lowconsumers, medium consumers, high consumers, etc.) By classifying,grouping, or segmenting the data to be fused, a simplified or separatefusion process can be carried out for each segment. The smaller size ofthe segments (in comparison to the dataset(s) the segments compose)enables the fusion process to be performed more quickly and efficiently.In addition, the data classification, grouping, or segmentation canproduce better results that, for example, enable more accurateprediction of consumption behaviors.

While known fusion techniques typically rely on the use of distancefunctions or regression models to predict consumption behavior, theresulting predictions are not well-suited to classify or group therecords or observations within datasets to be fused into discreteclasses or groups. For instance, as noted above, it may be desirable tosegment, classify, or group the observations or records within thedatasets into classes or groups such as non-consumers, high consumers,medium consumers, and low consumers. However, regression models anddistance functions are specifically adapted to predict information(e.g., usage or consumption information) that is inherently continuousin nature (e.g., dollars spent) rather than discrete such as, forexample, usage classifications or groups.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an example classification tree.

FIG. 2 depicts an example method of classifying or grouping data for usein a data fusion process.

FIG. 3 depicts an example method of generating node values for use inimplementing the example node analysis process of FIG. 2.

FIG. 4 depicts in greater detail the manner in which a plurality ofvalues may be generated for a given node based on relationships betweenthe probability of occurrence of each class or group at the node and theprobability of the occurrence of the classes within the overallpopulation.

FIG. 5 depicts an example set of values that may be generated for aplurality of classification tree nodes using the node analysis processof FIG. 2.

FIG. 6 depicts an example manner of implementing the node groupingprocess of FIG. 2.

FIG. 7 depicts an example manner in which nodes may be grouped using theexample node grouping process of FIG. 6.

FIG. 8 depicts an example apparatus that may be used to classify andfuse data.

FIG. 9 is example processor-based system that may be used to implementthe methods and apparatus described herein.

DETAILED DESCRIPTION

In general, the data classification methods, apparatus, and articles ofmanufacture described herein may be advantageously applied to enhance orimprove the operation and/or results of data fusion processes.Specifically, the methods, apparatus, and articles of manufacturedescribed herein analyze the nodes of a data classification tree toselectively form an arrangement or groups of nodes to representrespective classes, or groups associated with one or more databases ordatasets. The groups of nodes are then used to classify each of therecords within the database(s) or dataset(s) to be fused and theclassified records may then be fused according to the classifications.

Before providing a detailed discussion of the above-outlined dataclassification methods, apparatus, and articles of manufacture, ageneral discussion of data classification trees is provided. In general,data classification trees or classification tree models are onewell-known manner of classifying, grouping, or otherwise segmentingdata. Typically, the classifications, groups, segments, etc. representdiscrete usage classes or groups and, thus, typically represent aparticular type of consumer behavior. For instance, it may be desirableto classify, group, or segment consumer data records or observationsinto high, medium, low, and non-consumption groups, or classes.Classifying, grouping, or segmenting consumer data records in thismanner may help to provide a more intuitive understanding of the profileof a population, which may facilitate the selection of effectiveadvertising types and time slots, product developments and, moregenerally, can facilitate targeted marketing efforts toward certainmembers of the population.

Classification trees or models are typically composed of a set of rulesby which data (e.g., records or observations, each of which maycorrespond to a person, a household, etc.) within one or more datasetsor databases can be classified, grouped, segmented, etc. into aplurality of discrete classes, groups, or segments. A set of descriptivevariables (e.g., demographic information, psychographic information,etc.) may be logically interrelated in a hierarchical (e.g., tree-like)data structure according to the values of the variables. The lowesthierarchical level of the classification tree terminates in a set ofnodes (i.e., terminal nodes), which are commonly referred to as leaves.Each terminal node or leaf is typically associated with or correspondsto one group, class, or segment and more than one of the terminal nodesmay correspond to a given group, class, or segment. Each leaf orterminal node may then reflect a particular type of behavior (e.g.,consumption behavior) that is known to be consistent with the class,group, or segment associated with the node.

In practice, the terminal nodes of a classification tree are notperfectly predictive but, instead, are probabilistic in nature and,thus, the class or group associated with each of the nodes is apredicted class or group. In this manner, each terminal node or leaf maybe thought of as a likelihood, probability, or prediction that a datarecord or observation processed by the classification tree model orhierarchy is actually a member of the class or group with which it isassociated according to the classification tree or model.

Typically, the class, group, or segment (e.g., type of consumptionbehavior) that occurs most frequently or that is most likely to occurfor the data records associated with each terminal node determines thepredicted class or group for that terminal node. Thus, when a dataset orplurality of data records are grouped or classified according to theclassification tree, each terminal node may be associated with afrequency distribution of all or some of the classes or groups predictedby the tree. In other words, for each terminal node or leaf, there is atleast some probability that data actually associated with each of thepossible classes or groups will occur (i.e., will be classified ormisclassified) at that node. However, the probability with which each ofthe possible classes occurs at a given node will typically vary fromclass to class as well as node to node. Again, as noted above, the classor group that is most likely to occur at a given terminal node typicallydetermines the class or group assigned to that node and, thus,determines the classification or grouping of any data that is associatedwith that node as a result of being processed by the classificationtree.

As can be appreciated from the foregoing, because each terminal node isassigned to correspond to only one class or group (i.e., each terminalnode is used to predict only one class or group) and because theprobabilistic nature of the nodes results in data actually associatedwith multiple classes being associated with each node, misclassificationof data records can occur. For example, a classification tree mayprocess a data record actually associated with a non-consumer andassociate that record with a terminal node that is assigned to predicthigh volume consumers (e.g., classify a respondent that is actually anon-consumer as a high consumer). Thus, each terminal node typically hasan associated error rate (i.e., a likelihood of misprediction ormisclassification) that can be quantified and which is typicallyacceptable in view of the likelihood or probability that data recordsassociated with that node by the classification tree are classified orgrouped correctly.

In one example, the above-outlined data classification methods,apparatus, and articles of manufacture identify classification treeinformation such as, for example, the variables, the hierarchicalrelationships between the variables, the terminal nodes or nodes, theclasses or groups to which the nodes originally correspond, etc. Theclasses or groups may correspond to usage or consumption classes or anyother behavioral characteristic associated with a population ofindividuals, households, etc. However, as described in greater detailbelow, the classes or groups to which the nodes originally correspondmay be changed or modified based on an analysis of the ability of thenodes to effectively predict the actual class or group to which datarecords belong. The classification tree information may be stored in asuitable data structure and/or retrieved from a volatile and/ornon-volatile memory.

Analysis of the nodes of the classification tree begins by assigningeach of the nodes a plurality of values, where each of the plurality ofvalues is indicative of a relationship between that node and only one ofthe classes or groups associated with the nodes. The plurality of valuesassociated with each of the nodes may be representative of a frequencydistribution of the classes at that node (e.g., the frequency ofoccurrence, probability of occurrence, etc. for each of the classes atthat node). In particular, each of the plurality of values may be anindex value or ratio associated with the likelihood that a data recordactually associated with a particular one of the classes or groups willbe associated with the node corresponding to the value and, thus,predicted or classified (correctly or incorrectly) to have behavior(s)similar or identical to those associated with the class or groupassigned to the node. The index values or ratios may be determined basedon a comparison (e.g., a division) of the frequency of occurrence of aparticular class at a node and the frequency of occurrence of theparticular class within the population as a whole.

Continuing with the example, the node values may then be compared andeach node may be assigned to one of the classes or groups based on thecomparison. In particular, a class or group code may be assigned orotherwise associated with each node, where each class or group codecorresponds to only one of the possible classes or groups associatedwith the nodes of the classification tree. Thus, each of the nodes isassigned to only one of the classes or groups and, in some cases, atleast two of the nodes have the same class or group code. As a result,each of the nodes may become associated with a modified predicted classor group relative to the class or group originally associated with thatnode prior to the analysis of the classification tree nodes.

In general, the nodes may be assigned to the classes or groups using aniterative process (e.g., a process that may make multiple passes throughthe node value information) in which relatively larger node valuespreferably determine the class or group to which each of the nodes isassigned. In some cases, a previously assigned node may be re-assignedto another class or group for which that node has a larger or otherwisebetter value.

After the nodes have been assigned to the classes or groups, the datarecords or observations from one or more datasets or databases may beclassified based on the assignment of the nodes to the classes orgroups. More specifically, each data record or observation from thedataset or database may be analyzed using the classification tree todetermine a terminal node that corresponds to the data record orobservation. In other words, each data record or observation is analyzedusing the classification tree and becomes associated with a particularone of the terminal nodes of the classification tree. The classes orgroups to which the terminal nodes have been assigned as a result of theforegoing analysis are then associated with (e.g., by adding class orgroup identifying information to) the corresponding data records orobservation to classify those data records or observations.

Following the classification of the data records or observationsaccording to the classification tree and the modified predicted classesas set forth above, the classified data records or observations may befused using fusion methods and apparatus such as, for example, themethods and apparatus disclosed in co-pending international patentapplication number PCT/US03/33392, the disclosure of which is herebyincorporated in its entirety.

Now turning to FIG. 1, an example classification tree 100 is depicted indiagrammatic form. The example classification tree 100 includes aplurality of variables 102, 104, 106, 108, and 110, which may be relatedto demographic, psychographic, and/or other characteristics of apopulation of individuals, households, etc. The example classificationtree 100 also includes a plurality of terminal nodes N₁, N₂, N₃, N₄, N₅,and N₆, each of which is associated with a particular class, or group ofthe population. In turn, each class, or group corresponds to aparticular type of behavior such as, for example, a consumption or usagebehavior. For example, the nodes N₁ and N₄ may correspond to a mediumusage or consumption level, the node N₂ may correspond to a high usageor consumption level, the nodes N₃ and N₅ may correspond to a low usageor consumption level, and the node N₆ may correspond to non-users ornon-consumers.

In the example classification tree 100 of FIG. 1, the variable 102corresponds to the respondent's household size, the variable 104corresponds to respondent age, the variable 106 corresponds to thegeographic region in which the respondent's household is located, thevariable 108 corresponds to the number of children in the respondent'shousehold, and the variable 110 also corresponds to the geographicregion in which the respondent's household is located. Each of the datarecords or observations (i.e., respondent records or observations)within a dataset or database to be analyzed using the exampleclassification tree 100 contains values corresponding to the variables102, 104, 106, 108, and 110.

A known method of using the example classification tree 100 to classifya respondent or other data record begins by retrieving the record from adataset or database. Then, a value representative of household size isextracted from the record. If the extracted value representative of thehousehold size is equal to one, then the record is associated with theterminal node N₆, which corresponds to non-users, and the record (and,thus, the respondent associated with the record) is classified as anon-user.

On the other hand, if the household size is greater than or equal totwo, then a value representative of the age of the respondent associatedwith the record is extracted from the record. If the age of therespondent is 23-29 or 31-47, then a value representative of thegeographic region in which the respondent's household is located isextracted from the record. If the geographic region is the northeast,then the record is associated with the terminal node N₂, whichcorresponds to high users, and the record (and, thus, the respondentassociated with the record) is classified as a high user (i.e., a highconsumption user). On the other hand, if the geographic region is notthe northeast, then the record is associated with the terminal node N₁,which corresponds to medium users, and the record (and, thus, therespondent associated with the record) is classified as a medium user.

If the age of the respondent is not 23-29 or 31-47, then a valuerepresentative of the number of children in the respondent's householdis extracted from the record. If there are no children in therespondent's household, then the record is associated with the terminalnode N₅, which corresponds to low users, and the respondent record (and,thus, the respondent associated with the record) is classified as a lowuser.

On the other hand, if there are one or more children in the respondent'shousehold, then the value representative of the geographic region inwhich the respondent's household is located is extracted from therecord. If the respondent's household is located in the west, then therespondent is associated with the terminal node N₃, which corresponds tolow users, and the record (and, thus, the respondent associated with therecord) is classified as a low user. If the respondent's household isnot located in the west, then the respondent record is associated withthe terminal node N₄, which corresponds to medium users, and the record(and, thus, the respondent associated with the record) is classified asa medium user.

Thus, the above-described known manner of using a classification tree toclassify data records analyzes the values associated with certainvariables within each data record to determine which terminal node and,thus, which usage class, should be associated with that data record. Ofcourse, as noted above, each of the terminal nodes (e.g., the nodes N₁,N₂, N₃, N₄, N₅, and N₆) is probabilistic in nature and, thus, predictiveof the actual classification of the data record. As a result, theexample classification tree 100 and known analysis method describedabove may properly classify some records, while other records aremisclassified. However, typically, the degree to which a classificationtree misclassifies can be quantified and such a tree may be refined toreduce the probability of misclassification to an acceptable level.

FIG. 2 depicts an example method 200 of classifying or grouping data foruse in a data fusion process. Before discussing the example method 200in detail, it should be recognized that the operations or blocks shownin FIG. 2 may be implemented as machine readable or accessibleinstructions that can be executed via a processor system such as theexample processor system 902 depicted in FIG. 9. Additionally oralternatively, some of all of the operations or blocks shown in FIG. 2may be implemented using hardware, firmware, software, or anycombination thereof. Still further, the order of the blocks oroperations shown in FIG. 2 may be changed and/or one or more of theoperations or blocks may be eliminated, if desired.

Now turning in detail to the example method 200 of FIG. 2, aclassification tree model is generated (block 202) for the purpose ofanalyzing one or more datasets or databases to classify the records orobservations therein. For example, a classification tree similar oridentical to the example classification tree 100 shown in FIG. 1 may begenerated and stored in a suitable data structure in a memory or othermachine accessible medium. Of course, the variables and hierarchicalrelationships between the variables that compose such a classificationtree are carefully selected to accurately predict into which of aplurality of predetermined classes or groups the data records orobservations of a dataset or database can be categorized, segmented,etc. In any event, the classification tree may be generated at block 202using any known technique. Thus, further details relating to the mannerin which such a classification tree may be generated are not providedherein.

The example method 200 then analyzes the terminal nodes of theclassification tree (block 204). In general, the node analysis process204 may generate or assign a plurality of values to each of the nodes(e.g., the nodes N₁, N₂, N₃, N₄, N₅, and N₆ of the exampleclassification tree 100 of FIG. 1), where each of the plurality ofvalues assigned to a given node corresponds to only one class, or groupassociated with the population of records or observations to beanalyzed. Additionally, as described in greater detail below inconnection with FIGS. 3 and 4, each of the values for a given node maybe an index value that represents a relationship (e.g., a ratio) betweenthe probability that (or the frequency with which) a particular group orclass occurs at the given node and the probability or frequency ofoccurrence of the particular group or class within the overallpopulation. In this manner, the values (e.g., index values) calculatedfor each node represent how the distribution of classes at that nodediffers from the distribution of classes in the overall population.

In addition to generating a value corresponding to each of the possibleclasses, or groups for each node, the node analysis process 204generates a value representative of the proportion of an overallpopulation that will be associated with each of the nodes. For example,as described in greater detail in connection with FIG. 5 below, a valuerepresentative a of sum-of-weights or population projection for eachnode can be generated for each node. The values representative of theproportion of the overall population that is associated with the nodesmay be used to determine a relative size or importance of each of thenodes.

After performance of the node analysis process (block 204), the nodesare grouped or arranged using the node values generated at block 204according to class or group codes, where each class or group codecorresponds to only one class, or group (e.g., a usage or consumptionclass) (block 206). As described in greater detail in connection withFIGS. 6 and 7 below, the grouping or arrangement of nodes may be aniterative process in which nodes are assigned, grouped, or arranged sothat nodes best able to predict a particular class or group areassociated with a class or group code corresponding to that particularclass or group. Further, the grouping or arrangement of nodes isperformed so that the sum-of-weights of (or sum of probabilitiesassociated with) the nodes assigned to each of the class or group codes,each of which corresponds to only one of the classes or groups, issimilar or substantially equal to the probability of occurrence of theclass or group associated with the class or group code within theoverall population. Following the grouping or arrangement process (block206), the class or group code to which a given node is assigned may bethe same or different from the class or group originally correspondingto the node.

In contrast to the node grouping or arrangement process (block 206)described herein, known classification tree methods typically classify anode as the class that most frequently occurs at that node, regardlessof the characteristics of the overall population, regardless of therelative importance or size of the node in comparison to the overallpopulation and other nodes, and regardless of the overall effectivenessof the classification tree at accurately predicting or classifying datarecords or observations.

After performance of the node grouping or arrangement process (block206), the node grouping or arrangement (e.g., the example node groupingof FIG. 7) may be used to assign class codes to data records orobservations to thereby classify the data records or observations (block208). In general, each data record may be processed using aclassification tree (e.g., similar to the manner in which the exampleclassification tree 100 may be used to analyze or process data recordsas described above) to determine which terminal node should beassociated with the data record. Then, a node grouping or arrangement(e.g., similar to the example node grouping or arrangement depicted inFIG. 7) may be used to assign a class or group code (and, thus, amodified predicted class or group) to that node. If desired, theassigned class or group code may be inserted in the data record orotherwise associated with the data record.

Finally, the data records, including their assigned class codes, may befused using the class codes to guide or otherwise facilitate the fusionprocess (block 210). For example, in the case of a fold-over fusion(i.e., where an original dataset or database is split into two datasetsor databases), the assigned class codes may be inserted as matchingvariables. Additionally or alternatively, the assigned class or groupcodes may be used to segment one or more datasets or databases toenhance the overall performance of a fusion process on the one or moredatasets or databases.

FIG. 3 depicts an example method 300 of generating node values for usein implementing the example node analysis process (block 204) of FIG. 2.Initially, the example method 300 determines a distribution of classesor groups for a selected node (block 302). For example, a frequencydistribution, probability distribution, etc. of classes or groups at theselected node may be used. A plurality of values may then be generatedfor the selected node (block 304). For example, the values may begenerated to reflect a relationship between the frequency or probabilitydistribution values associated with the classes or groups at theselected node and the distribution of classes or groups within anoverall population.

In any event, after the values are generated for the selected node(block 304), the example method 300 determines if there are more nodesto process (block 306). If there are more nodes for which values need tobe generated, then control returns to the block 302. On the other hand,if there are no more nodes to process, then the example method 300 endsor returns control to, for example, the example method 200 of FIG. 2.

FIG. 4 depicts in greater detail the manner in which a plurality ofvalues may be generated for a given node based on relationships betweenthe probability of occurrence of each class or group at the node and theprobability of the occurrence of the classes within the overallpopulation. As shown in the example of FIG. 4, each class (i.e.,non-users, low, etc.) is associated a probability or frequency ofoccurrence within the overall population. For example, non-users accountfor 40% of the overall population. In addition, each of the fourpossible classes or groups has an associated probability or frequency ofoccurrence at the node N₅. For example, there is a 36% probability thata non-user will occur at the node N₅. The values in the column labeledN₅ in FIG. 4 may be determined at, for example, block 302 of the examplemethod 300 of FIG. 3. The index values for the node N₅ are generated foreach of the classes (e.g., at block 304 of FIG. 3) by dividing theprobability of occurrence of a class at the node (e.g., the node N₅) bythe probability of occurrence of the class in the overall population.For example, the index value for non-users (i.e., 90) is generated bydividing 36% by 40%. It should be recognized that with knownclassification tree methods, the node N₅ would have simply beenclassified as a non-user node because the most frequently occurringclass at the node N₅ is non-users (i.e., non-users occur 36% of thetime). However, as described in greater detail in connection with FIG. 6below, the index values may be used to change the classification of anode to better predict the actual class or group of a data records. Forexample, as depicted in FIG. 4, the largest index value for the node N₅occurs for the class “low,” which suggests that the node N₅ could bebetter used to predict low users rather than non-users.

FIG. 5 depicts an example set of values or analysis results that may begenerated for a plurality of classification tree nodes using the nodeanalysis process (block 204) of FIG. 2. As shown in the example of FIG.5, each of the nodes N₀ through N₉ has a plurality of index valuesassociated therewith that may be generated as described above inconnection with FIGS. 3 and 4. In addition, each of the nodes in theexample of FIG. 5 is also associated with a value representative of itsimportance relative to the overall population. For example, about 5% ofthe data records are associated with the node N₀, whereas about 25% ofthe data records are associated with the node N₃. Also, the probabilityof occurrence of each of the four classes or groups within the overallpopulation is included in the example analysis results of FIG. 5. Theinformation depicted in the example of FIG. 5 may, for example, bestored in a memory using any desired data structure such as, forexample, one or more tables, linked lists, arrays, etc. Further, whilethe example of FIG. 5 depicts index values as being used as theplurality of values representative of each of the nodes, other valuescould be used instead. For example, other values representative of arelationship between the occurrence of a particular class or classes orgroups at each of the nodes and the characteristics of the populationcould be used instead.

FIG. 6 depicts an example manner of implementing the node groupingprocess (block 206) of FIG. 2. The example method 600 depicted in FIG. 6is described below by way of example in connection with the example setof node values or analysis results of FIG. 5 and the example nodegrouping depicted in FIG. 7. In general, the example method 600 may beused to iteratively examine the example node analysis results shown inFIG. 5 to assign class or group codes to the nodes as shown in exampleof FIG. 7.

Now turning in detail to FIG. 6, the example method 600 selects a groupor class to examine or process (block 602). More specifically, theexample method 600 selects one of the four classes or groups (i.e.,columns) of example node analysis results of FIG. 5. While the examplemethod 600 could select any of the groups or classes (i.e., columns) inany order or sequence, the example described below first selects thehigh consumption or usage class followed by medium, low, and thennon-users (i.e., moves sequentially from right to left across theexample node analysis results of FIG. 5 one or more times). Moving fromright to left across the example data of FIG. 5 (i.e., beginning thegrouping process by starting with the rightmost column) will tend toresult in a final grouping or arrangement of nodes (e.g., the examplenode grouping of FIG. 7) that more accurately identifies those datarecords that should be classified in the high consumption or usage classor group. In this manner, marketing efforts may, for example, be bettertargeted toward a particular class or group (e.g., the high consumptionclass or group).

While the example method 600 is described as moving from right to leftacross the columns of class or group data depicted in FIG. 5, theexample method 600 could select groups or portions of data at block 602in different manners. For example, the example method 600 could movefrom left to right beginning with the non-user class or group, the classor group data could be selected according to a predetermined order orsequence (e.g., medium, then low, then non, followed by high), the classor group data could be selected in a random fashion, the class or groupdata could be selected in a varying sequence depending on the progressof the grouping process, etc.

In any event, in this example, the high usage class or group is firstselected at block 602 and the example method 600 then selects anavailable node (initially all nodes are available) that is unassigned tothe current group or class (i.e., the high usage class) and which hasthe largest value (e.g., index value) (block 604). Thus, in thisexample, the node N₆ is selected at block 604 because it is available,unassigned to the high usage class, and has the highest index value(i.e., 160). Then, the example method 600 determines if the selectednode (i.e., N₆) is assigned to another group (i.e., one of the groups 1,2, 3, or 4 shown in FIG. 7) (block 606). In this case, the node N₆ isnot assigned to another group or class and the example method 600determines if the group associated with high usage class (i.e., thegroup or class having the class code 4 shown in FIG. 7) can accept thenode N₆ (block 608).

The method 600 determines if a group can accept a selected node (block608) by comparing the total sum-of-weights assigned to the group(including the currently selected node) to the total weight the group orclass has within the overall population. For example, continuing withthe example, the currently selected node N₆ contributes a weight of 10%of the total population, there are no other nodes currently assigned thehigh usage group (i.e., group 4) so the total sum-of-weights would be10% if the node N₆ were added to the group 4, and the total weight ofgroup 4 (i.e., the high usage class) is 20% of the total population.Accordingly, the example method 600 determines at block 608 that group4, which corresponds to the high usage class or group, can accept thenode N₆ and assigns the node N₆ to group 4 (block 610).

After assigning the node N₆ to group 4, the example method 600determines if group 4 is full (block 612). A group is full if the totalweight of the nodes (i.e., the sum-of-weights) currently assigned to thegroup is equal to or exceeds the total weight of the class or groupwithin the overall population. In the case of group 4, group 4 is fullif the sum of weights assigned to group 4 equals or exceeds 20%.Continuing with the example, after the node N₆ is assigned to group 4 atblock 610, the example method 600 determines at block 612 that group 4is not full and then determines if there are any remaining availablenodes (in the high usage column of the data of FIG. 5) that are not yetassigned to group 4 (block 614). Only the node N₆ has been assigned togroup 4 and, as a result, the method 600 determines at block 614 thatthere are available, unassigned nodes and returns control to block 604.

The example method 600 then continues in the above-described manner tonext assign the node N₉ (which has an index value of 140 and a weight of5%) and the node N₂ (which has an index value of 120 and a weight of 5%)to group 4. After the node N₂ is assigned to group 4, the method 600determines at block 612 that group 4 is full because the sum-of-weightsassigned to group 4 equals 20%, which is the proportion of the overallpopulation that should fall within the high usage class or group. Afterdetermining that group 4 is full at block 612, the method 600 determinesif there are any currently unassigned nodes (i.e., nodes which have notbeen assigned to any group or class) (block 616). At this point, thenodes N₁, N₃, N₄, N₅, N₇, and N₈ have not yet been assigned and, thus,the method 600 returns control to block 602 to select the next group.

In this example, after first processing the data in the high usagecolumn of the data of FIG. 5 to form group 4, the method 600 nextselects (block 602) the data in the medium usage class or column of thedata in FIG. 5 to begin forming group 3 shown in FIG. 7. However, atblock 604, the method 600 selects the node N₂, which has already beenassigned to group 4, for assignment to group 3 (block 604). Then, atblock 606 the method 600 determines that the node N₂ has already beenassigned to group 4 and determines if the node value (i.e., its indexvalue) in the current group or class (i.e., group 3 or the medium usageclass or group) is greater than the node value in the group to which thenode is currently assigned (i.e., group 4 or the high usage class orgroup) (block 618). In this case, the index value of the node N₂ is 155in group 3 (i.e., the medium usage class or group) and 120 in group 4 orthe high usage class or group. Thus, because the index value 155 isgreater than 120 at block 618, the method 600 passes control to block608. The method 600 then determines that group 3 can accept the node N₂because the sum-of-weights assigned to group 3, including the node N₂does not exceed the total permissible weight of group 3 (i.e., 20%)within the overall population. The method 600 then assigns the node N₂to group 3 (and, thus, de-assigns the node N₂ from group 4) at block610, determines that group 3 is not full at block 612, determines thatthere are available, unassigned nodes for potential assignment to group3 at block 614, and returns control to block 604.

The method 600 then continues and assigns the node N₈ to group 3, whichresults in group 3 being full at block 612 and selection of group 2 forprocessing when the method returns control to block 602. The method 600continues processing for node assignments to group 2 in theabove-described manner so that the nodes N₁, N₅, and N₀ are assigned togroup 2. The nodes N₃ and N₇ are not assigned to group 2 because thesum-of-weights resulting from the assignment of either of these nodes togroup 2 as determined at block 608 would exceed the permissible total of20%, which is the total weight of the low usage group or class withinthe overall population. Thus, the method determines at block 608 thatgroup 2 cannot accept either of the nodes N₃ and N₇ and makes thosenodes unavailable to group 2 at block 620.

In addition, the method 600 may employ a tie-breaking scheme in theevent that multiple nodes having the same value associated with thecurrent usage class or group. For example, when assigning nodes to group2, the method 600 may recognize that either of the nodes N₀ or N₄ (bothof which have an index value of 110) could be assigned to group 2. Inresponse, the method 600 may simply select the lower of the nodenumbers, may select the node having a lowest value in comparison to theother nodes within a group or class in which none of the tied nodes havebeen assigned, or may employ any other tie-breaking scheme.

After assigning the nodes N₃ and N₇ to group 1, the method 600determines at block 616 that the node N₄ has not been assigned and themethod returns control to block 602, which again selects group 4 forprocessing (i.e. the method 600 begins to iterate through the groupsagain). During the second pass of the method 600 through the groups, themethod 600 attempts to again first select the node N₂ for assignment togroup 4 because it is indicated as available to group 4 and has thelargest value among the nodes that are not currently assigned to group4. However during this pass, the method 600 determines that the node N₂is assigned to group 3 (block 606) and that the value of the node N₂ ingroup 4 (i.e., 120) is not greater than the value of the node N₂ ingroup 3 (i.e., 155). As a result, the method passes control to block 620and makes the node N₂ unavailable to group 4. The method 600 thencontinues and assigns the node N₄ to group 4. After the methoddetermines at block 616 that all the nodes have been assigned, themethod 600 ends or returns control to, for example, the example methodof FIG. 2. In the above-described example, the final assignments of thenodes to the groups 1, 2, 3, and 4 are shown in FIG. 7.

FIG. 8 depicts an example apparatus 800 that may be used to classify andfuse data. As depicted in FIG. 8, the example apparatus 800 includes aclassification tree generator 802, a node analyzer 804, a node grouper806, a class code assignor 808, a fuser 810, and a mass storage unit812, all of which are coupled as shown. More specifically, theclassification tree generator 802 may be configured to perform theoperations of block 202 of FIG. 2 to generate a classification tree suchas, for example, the example classification tree 100 of FIG. 1. The nodeanalyzer 804 may be configured to perform the node analysis operationsof block 204 of FIG. 2 and the operations shown in FIG. 3 to generatethe example node analysis results of FIG. 5. The node grouper 806 may beconfigured to perform the operations of block 206 of FIG. 2 and theoperations of FIG. 6 to generate the example node grouping depicted inFIG. 7. The class code assignor 808 and the fuser 810 may be configuredto perform the operations of blocks 208 and 210, respectively, of FIG.2. The mass storage unit 812 may be configured to store classificationtree data such as that depicted in FIG. 1, as well as node analysisresults such as those shown in FIG. 5 and node grouping results such asthose shown in FIG. 7. The mass storage unit 812 may be implementedusing any desired machine accessible medium including solid statevolatile and/or non-volatile memory, optical media, magnetic media, etc.

Also, it should be recognized that any or all of the structure shown inthe example system 800 of FIG. 8 may be implemented using primarilysoftware, firmware or instructions stored on a machine accessible mediumand executed by a processor and/or may be implemented using primarilyhardware, including one or more application specific integratedcircuits, discrete semiconductor devices, passive components, logiccircuitry, analog circuitry, etc. Alternatively, any desired combinationof hardware, software and/or firmware may be used.

The methods described herein (e.g., the example methods depicted inFIGS. 2, 3 and 6) may be implemented using instructions or code storedon a machine readable or accessible medium that, when executed, cause amachine to perform all or part of the methods. For example, theinstructions or code may be a program for execution within by aprocessor, such as the processor 900 within the example processor-basedsystem 902 depicted in FIG. 9. The program may be embodied in softwarestored on a tangible medium such as a CD-ROM, a floppy disk, a diskdrive, a digital versatile disk (DVD), or a memory associated with theprocessor 900, but persons of ordinary skill in the art will readilyappreciate that the entire program and/or parts thereof couldalternatively be executed by a device other than the processor 900and/or embodied in firmware or dedicated hardware in a well-knownmanner. For example, any or all of the blocks shown in FIGS. 2, 3, and 6could be implemented by software, hardware, and/or firmware. Further,although the example methods are described with reference to the flowdiagrams illustrated in FIGS. 2, 3 and 6, persons of ordinary skill inthe art will readily appreciate that many other methods of implementingthe methods described herein may alternatively be used. For example, theorder of execution of the blocks may be changed, and/or some of theblocks described may be changed, eliminated, or combined.

Now turning in detail to FIG. 9, the example processor-based system 902may be, for example, a server, a personal computer, a personal digitalassistant (PDA), an Internet appliance, a DVD player, a CD player, adigital video recorder, a personal video recorder, a set top box, or anyother type of computing device.

The processor 900 may, for example, be implemented using one or moreIntel® microprocessors from the Pentium® family, the Itanium® family orthe XScale® family. Of course, other processors from other families arealso appropriate.

The processor 900 is in communication with a main memory including avolatile memory 904 and a non-volatile memory 906 via a bus 908. Thevolatile memory 904 may be implemented by Synchronous Dynamic RandomAccess Memory (SDRAM), Dynamic Random Access Memory (DRAM), RAMBUSDynamic Random Access Memory (RDRAM) and/or any other type of randomaccess memory device. The non-volatile memory 906 may be implemented byflash memory and/or any other desired type of memory device. Access tothe memory 904 is typically controlled by a memory controller (notshown) in a conventional manner.

The system 902 also includes a conventional interface circuit 910. Theinterface circuit 910 may be implemented by any type of well-knowninterface standard, such as an Ethernet interface, a universal serialbus (USB), and/or a third generation input/output (3GIO) interface.

One or more input devices 912 are connected to the interface circuit910. The input device(s) 912 permit a user to enter data and commandsinto the processor 900. The input device(s) can be implemented by, forexample, a keyboard, a mouse, a touchscreen, a track-pad, a trackball,isopoint and/or a voice recognition system.

One or more output devices 914 are also connected to the interfacecircuit 910. The output devices 914 can be implemented, for example, bydisplay devices (e.g., a liquid crystal display, a cathode ray tubedisplay (CRT), a printer and/or speakers). The interface circuit 910,thus, typically includes a graphics driver card.

The interface circuit 910 also includes a communication device such as amodem or network interface card to facilitate exchange of data withexternal computers via a network 916 (e.g., an Ethernet connection, adigital subscriber line (DSL), a telephone line, coaxial cable, acellular telephone system, etc.).

The system 902 also includes one or more mass storage devices 918 forstoring software and data. Examples of such mass storage devices includefloppy disk drives, hard drive disks, compact disk drives and digitalversatile disk (DVD) drives.

Although certain methods and apparatus and articles of manufacture havebeen described herein, the scope of coverage of this patent is notlimited thereto. To the contrary, this patent covers all methods,apparatus and articles of manufacture fairly falling within the scope ofthe appended claims either literally or under the doctrine ofequivalents.

1. A computer implemented method of classifying data, comprising:selectively grouping nodes of a classification tree so that each node isassigned to only one of a plurality of groups and so that at least oneof the groups includes at least two of the nodes; classifying the databased on the classification tree and the selective grouping of thenodes; and displaying the classified data results.
 2. A method asdefined in claim 1, wherein selectively grouping the nodes includesassigning each of the nodes to one of the groups based on valuesassociated with the nodes, wherein each of the values is representativeof a relationship between its respective node and one of the groups. 3.A method as defined in claim 2, wherein the each of the values isassociated with a frequency distribution, a probability, or an indexvalue.
 4. A method as defined in claim 1, wherein selectively groupingthe nodes includes comparing values associated with the nodes andassigning each of the nodes to one of the groups based on thecomparisons.
 5. A method as defined in claim 4, wherein comparing thevalues associated with the nodes and assigning each of the nodes to oneof the groups based on the comparisons includes re-assigning at leastone of the nodes from a first one of the groups to a second one of thegroups.
 6. A method as defined in claim 1, wherein selectively groupingthe nodes includes selectively grouping the nodes in accordance with anoverall population frequency distribution of the groups.
 7. A method asdefined in claim 1, wherein classifying the data based on the selectivegrouping of the nodes includes assigning group identifying informationto each of a plurality of data records comprising the data so that eachof the plurality of the data records is associated with only one of thegroups.
 8. A method as defined in claim 7, further comprising fusing thedata records based on the group identifying information.
 9. An apparatusfor classifying data, comprising: a memory; and a processor coupled to amemory and configured to: selectively group nodes of a classificationtree so that each node is assigned to only one of a plurality of groupsand so that at least one of the groups includes at least two of thenodes; classify the data based on the classification tree and theselective grouping of the nodes; and display the classified dataresults.
 10. An apparatus as defined in claim 9, wherein the processoris configured to selectively group the nodes by assigning each of thenodes to one of the groups based on values associated with the nodes,wherein each of the values is representative of a relationship betweenits respective node and one of the groups.
 11. An apparatus as definedin claim 10, wherein the each of the values is associated with afrequency distribution, a probability, or an index value.
 12. Anapparatus as defined in claim 9, wherein the processor is configured toselectively group the nodes by comparing values associated with thenodes and assigning each of the nodes to one of the groups based on thecomparisons.
 13. An apparatus as defined in claim 12, wherein theprocessor is configured to compare the values associated with the nodesand assign each of the nodes to one of the groups based on thecomparisons by re-assigning at least one of the nodes from a first oneof the groups to a second one of the groups.
 14. An apparatus as definedin claim 9, wherein the processor is configured to selectively group thenodes by selectively grouping the nodes in accordance with an overallpopulation frequency distribution of the groups.
 15. An apparatus asdefined in claim 9, wherein the processor is configured to classify thedata based on the selective grouping of the nodes by assigning groupidentifying information to each of a plurality of data recordscomprising the data so that each of the plurality of the data records isassociated with only one of the groups.
 16. An apparatus as defined inclaim 15, wherein the processor is configured to fuse the data recordsbased on the group identifying information.
 17. A machine accessiblemedium having instructions stored thereon that, when executed, cause themachine to: selectively group nodes of a classification tree so thateach node is assigned to only one of a plurality of groups and so thatat least one of the groups includes at least two of the nodes; classifydata based on the classification tree and the selective grouping of thenodes; and display the classified data results.
 18. A machine accessiblemedium as defined in claim 17, wherein the instructions, when executed,cause the machine to selectively group the nodes by assigning each ofthe nodes to one of the groups based on values associated with thenodes, wherein each of the values is representative of a relationshipbetween its respective node and one of the groups.
 19. A machineaccessible medium as defined in claim 18, wherein the each of the valuesis associated with frequency distribution, a probability, or an indexvalue.
 20. A machine accessible medium as defined in claim 17, whereinthe instructions, when executed, cause the machine to selectively groupthe nodes by comparing values associated with the nodes and assigningeach of the nodes to one of the groups based on the comparisons.
 21. Amachine accessible medium as defined in claim 20, wherein theinstructions, when executed, cause the machine to compare the valuesassociated with the nodes and assign each of the nodes to one of thegroups based on the comparisons by re-assigning at least one of thenodes from a first one of the groups to a second one of the groups. 22.A machine accessible medium as defined in claim 17, wherein theinstructions, when executed, cause the machine to selectively group thenodes by selectively grouping the nodes in accordance with an overallpopulation frequency distribution of the groups.
 23. A machineaccessible medium as defined in claim 17, wherein the instructions, whenexecuted, cause the machine to classify the data based on the selectivegrouping of the nodes by assigning group identifying information to eachof a plurality of data records comprising the data so that each of theplurality of the data records is associated with only one of the groups.24. A machine accessible medium as defined in claim 23, wherein theinstructions, when executed, cause the machine to fuse the data recordsbased on the group identifying information.
 25. An apparatus forclassifying data, comprising: a node analyzer configured to generate aplurality of values for each of a plurality of nodes of a classificationtree, wherein each of the plurality of values represents a relationshipbetween one of a plurality of classes and the characteristics of apopulation of data; a node grouper configured to group theclassification tree nodes so that each of a plurality of groupscorresponds to only one of the classes; a class code assignor configuredto use the groups to assign class codes to the data; and a display todisplay the classified data results.
 26. An apparatus as defined inclaim 25, wherein the node analyzer is configured to generate aplurality of index values, each of which represents a ratio of thelikelihood of occurrence of a class within a node and the likelihood ofoccurrence of a class within the population of data.
 27. An apparatus asdefined in claim 25, wherein the node grouper is configured re-assign atleast one of the classification tree nodes to one of the groups.
 28. Anapparatus as defined in claim 25, wherein the node grouper is configuredto assign each classification tree node to only one of the classes basedon comparisons of the values.
 29. An apparatus as defined in claim 25,wherein the node grouper is configured to assign the assigning theclassification tree nodes to the classes so that at least two nodes areassigned to the same class.